Electrical system for controlling the temperature of individual air streams



Oct- 14, 195 E. A. RUSSELL ETAL ELECTRICAL. SYSTEM FOR CONTROLLING THETEMPERATURE OF INDIVIDUAL. AIR STREAMS 72w Faber Filed Feb. 12, 1949Oct. 14, 1952 E. A. RUSSELL ETAL 2,613,919

ELECTRICAL SYSTEM FOR CONTROLLING THE TEMPERATURE OF INDIVIDUAL AIRSTREAMS Filed Feb. 12, 1949 4 Sheets-Sheet 2 22/14 0242 Q ZzzsaeZZ 7127202")? die/2m Faer I Ez'c yem Oct. 14, 1952 E. A. RUssELL ET ALELECTRICAL SYSTEM FOR CONTROLLING THE TEMPERATURE OF INDIVIDUAL AIRSTREAMS Filed Feb. 12, 1949 4 Sheets-Sheet 5 URETUIZU Oct. 14, 1952 RLL. Er AL 2,613,919

ELECTRICAL SYSTEM FOR CONTROLLING THE TEMPERATURE OF INDIVIDUAL AIRSTREAMS Filed Feb. 12, 1949 4 Sheets-Sheet 4 firzz w i HAW- a0 vvv M I76' 72 71- I 77 78 J65 INVENTORS.

g} Faber E Bid 6072/ Patented Oct. 14, 1 952 ELECTRICAL SYSTEM FORCONTROLLING THE TEMPERATURE OF INDIVIDUAL AIR STREAMS Edward A; Russelland Timothy J. Lehane, Chicago, and Robert E. Pidgeon, Round Lake, 111.,Y assignors to Vapor Heating Corporation, Chicago, 111., a corporationof Delaware Application February 12, 1949, Serial No. 75,992

15 Claims. (Cl. 257-3) This invention relates to an improved electri-.

cal system for controlling the temperature of av plurality of enclosuresby controlling the temperature of individual'streams of air divertedfrom a source of pretreated air (heated or cooled) and.

delivered into the several enclosures.

A principal object of the invention is to provide a control systemwhereby the occupants, of one or more separate. compartments of aseries, may maintain temperatures of their own liking in theirvindividual compartments, by suitably altering the air temperatureimmediately prior to its delivery into such compartments, withoutmaterially altering or affecting the temperature of other compartmentsserved by the same heat-- ing and/or cooling apparatus.

-According to the principles of the invention, air is preheated orcooled to provide a supply of air at apredetermined temperature and thisair is directed through separate passages into the individual enclosuresor into different sections of the same enclosure. the said supplied airis unsuitable for maintaining one or more of the enclosures at thetemper ature desired, thetemperatures of the individual streams of airdelivered to such enclosures-are altered, as hereinafter described,toprovide air.

at the desired temperatures.

. I'hetemperatures of the individual streams of air may be altered byblending air streams of different temperatures or by addingheat to theindividual air streams immediately prior to-the delivery of the air intothe enclosure. In the first case, a proportioning valve is utilized inconnection witheach air stream to vary the amount of, air of differenttemperatures used in the blended stream. If heat is added directly totheseparate streams of air, heater elements are posi-- tioned in the branchducts leading fromthe main source of pretreated air into the individualenclosures. v,

Itis a specific object of the invention-to pro vide an automaticcontrolsystem which can'be provided with a combined heating. and coolingsystem of a general type in which air streams of different temperaturesare blended'and'intro- When the temperature of 2 duced into one or moreof a series of enclosures. Fig. 2 is a diagrammatic plan view takensub-. stantially on line 2-2 of Fig. 1, showing the. arrangement ofindividual compartments and the overhead ducts for delivering heated orcooled air. into said compartments.

Fig. 3 is a cross-sectional view. taken through the car to show the airducts, thermostats, and the proportioning valves for controlling thedelivery of blended air into the car. I p

Fig. 4-. is a sectional view of one of said proportioning valves andameans for operating the same. I Y

Fig. 5 is a View similar to Fig. 3, but illustrates a modified system inwhich individual heaters are utilized to add heat to the air deliveredinto; the several compartments. ,7 Fig. -6 is a fragmentary view of themain air. heater and showing a solenoid inlet valve for controlling thedelivery of heating mediumthereto. v

Fig. '7 is a similar view of an air heater. and a solenoid valve forcontrolling the delivery of heating medium thereto. Fig. 8 illustratesone of the floor radiators, including its solenoid inlet valve.

Fig. 9 is a view showing, on a larger scale, one, of the individualheaters shown in Fig. 5 and ,a solenoid inlet valve associatedtherewith, and

Fig. 10 is a wiring' diagramof the improved. electrical control systemof the present invention.

The electrical control system of the present, invention is illustratedherein in connection with a combined heating and cooling system in whichthe'temperature of an enclosed space, or. of a; series of enclosedspaces, is altered by controlling the temperature of the air at thelocation where it is delivered into the enclosed space.

Accordingto the heating and cooling system. shown in Figs. .1 to4,inclusive,' air, after beingv heated or cooledto-a desiredtemperature, bymeans of a heater in or a cooler II, is forced. into amain air duct I2 composed of a primary section l3 and a return sectionI4. Both sections of the air duct extend substantially the full lengthof the main enclosure whose temperature is being controlled. The primarysection l3of the air duct connects at its .outer end 15 .with' thereturn section l4 so that air from the blower. It may flow through theprimary section l3 of the duct for the full length of the enclosure.-I1:, for example a railway car, and then flow through the returnsection [4 of the duct for the full length ofthe car.

Because of the combined lengths. oftjthe .air duct sections I3 andl4,.there is a progressive change in the temperature-of the air inproportion to the length of its travel within the air duct.Consequently, the temperature of the air changes in proportion to thelength of its travel from theheater' "19 or cooler ll. Therefore, inorder to deliver air at the desired temperature throughout the entirelength of the car, the air is taken from both duct sections I3 and M, atsuitable locations, and blended into air streams of the desiredtemperature. These blended streams of air are then delivered into theenclosed space or series of spaces, as the case may be.

The railway car 11, herein shown, by way of illustration, is subdividedinto a plwrality oi separate enclosures, known generally as "roomettes.The separate enclosures are relatively small and are arranged onopposite sides of a central aisle designated A. Inasmuch as theroomettes at opposite si es of the aisle are of like size and are servedby identical air ducts and control means, the present invention will bedescribed with reference to the enclosures located along one side onlyof the aisle. The va ou's ducts. radiators and control elements which"serve the enclosures on the other side of the aisle A will be designatedwith the same reference characters provided with an expoheat I. Theseveral roomettes along one side of the aisle A are designated B, C, Dand E. Thereare also certain open sections designated FandG whichcommunicate with the aisle A.

and are normally maintained at the same term peratureas the aisle.

*Plop'o'rtiohate amounts of air, at different temperatures, aredischarged from both duct sections N M through discharge ports lt-ltinto each of the several enclosed spaces (see Fig. 3'). This air isreceived and blended in branch ducts '29 leading from each pair ofdischarge ports to outlet grills 2'! which open through the ceiling ofthe roomettes.

'1 In-"addition'to the'mai-n air heater it, the improved system isprovided with an auxiliary heater '22 positioned in the air duct sectionM and a series of floor radiators 23, one for each enclcsed space BQC,D", E, F and G. The operation ofthe floor radiators. are controlled vbytemperature 'responsive means including thermostats 2 1 24, 24, "24 24"and 24' etc, responsive to the temperature of the several enclosedspaces in which the floor radiators are heated." The auxiliary airheater 22 is con"- trolled by a thermostat 25 locatedin the duct l3ahdset to function at 76 F. The said. heater 22 is alsodependent uponthe opening of at least one room thermostat, 24h, etc. Consequently, thesaid auxiliary air heater 22 is operat'ive only when the ducttemperature is below'the functional setting of the duct thermostat 25(76 F.) and when the temperature of at least one room B, C, D or 'E isbelow the functional setting of its thermostat.

"The several heating elements in, 22 and 23 are shown in Figs. 6, 7 and8, respectively, in con-- nection with conventional valve structures.The delivery or heating medium to main heater ID is -'c':ontrolle'd byinlet valve 26 which is normally closed by axspr'ing 21 and is opened toadmit heating medium, for example steam, to. the heater by energizationof solenoid 28. The condensation is discharged from heater it throughpipe 29. a

The heating medium to the auxiliary air heater 22 is controlled by meansof a valve 30 which is nor'mgally closedbya spring 31 and is opened '4by the energization of a solenoid 32. A drain pipe for discharging thespent heating medium is shown at 33.

Each floor radiator includes outer and inner concentric pipes. The innerpipe 34 leads from a valve casing 35 and delivers heating medium intothe outer pipe adjacent its outer end. The delivery of heating medium tothe inner pipe is controlled by a valve 36 which is normally held openby a spring 31 and closed by the energization of solenoid 38. Theheating medium enters valve casing 35 through pipe 39 and is dischargedfrom the radiator 23 through outlet pipe 40.

The air discharged from each port |8-l9 is controlled by a proportioningvalve 4|. This valve may be actuated by any suitable means 42, adaptedto be directly or indirectly controlled, electrically, in relation tothe temperature of the enclosed space receiving the blended air stream.In the disclosure in Figs. 1, 2 and 3, the means 42, for purpose ofconvenience, is illustrated in the form of a heat motor. Inasmuch as theheat motor, illustrated diagrammatically in Fig. 4, is V of knownconstruction and is fully disclosed in- Patent No. 2,391,342, a briefdescription of its structure and function will be sufiicient for thepresent disclosure. The said heat motor may be described briefly ascomprising an outer casing 42, a bellows element 42 enclosed in thecasing, and a heating coil I35 applied in an approved manner around theouter surface of the casing. The said casing is open only at one end.The bellows has a closed end portion M which extends into the casing 42and has an open end secured in the open end of said casing. The spacebetween the bellows and the said casing constitutes a closed chamber 42-for containing a temperature sensitive fluid. Each heat motor 42 and itsassociated valve 4! is operatively connected by means of a push rod 42which connects theclosed lower end of the bellows 42* with a pivotedlever 43. The valve and its operating means are so adjusted that thevalve 41, in one position of its operation, assumes a central positionso as to deliver equal amounts of air from the duct sections I3 and I4into the branch duct 20. .-If the temperature within the controlledspace associated with the heat motor 42 rises above a predeterminedtemperature, an electrical energizing current is directed through theheating coil of the heat motor so as to heat and thereby e'xpand thetemperature sensitive fluid so as to partially compress the bellows andthereby move the valve 4! in a direction toincrease the amount of coolair delivered from air duct section l4 and to proportionately decreasethe amount of higher temperature air delivered from the duct section [3.When the temperature ofthe roomette 'falls below the desired controlpoint the heat motor 42 is deenergized and therefore cools. The coolingofsaid motor moves the valve All in a direction to increase the amountof higher temperature air delivered into the blended air stream and tocorrespondingly decrease 'the amount of-cool'er air entering into saidblended air stream.

While the invention, as herein disclosed, inc udes the use of said heatmotor 42, various other forms of valve actuators may be used to adjustthe position of the valve 4 I.

During normal heating and cooling operations the air to be'heated orcooled is drawn from'the vestibule space 43 of the car, the air passingthrough suitable filters G l-45 before entering the blower I6 andprimary air duct l3. The air from each of the enclosures of the'car isnormally vented to the outside atmosphere through vent duct 46 whichlead from outlet grills 4'! to outlet duct 48 (Fig. 2). A valve 49 ispositioned in outlet duct 48 so as to normally direct the vented air tothe outside of the car. However, when it is desired to recirculate aportion of the vented air, the valve 49 may be adjusted toward thedotted line position shown in Fig. 2 so as tedirect all or a portion ofthe air into the air receiving chamber 50.

Referring now to the electric control system: The room thermostats 24',etc., for controlling the operation of the floor radiators 23 areprovided with auxiliary heaters 5l etc. Each thermostat 24 etc., isconnected in series with a variable resistor 52*, etc., whereby thefunctional setting of the individual thermostats may be adjusted. Therange of this adjustment, for the present disclosure, is 65 F. to 80 F.A thermostat 53, having an operating range from 63 F. to 76 F., islocated in the primary air duct [3 for controlling the operation of themain air heater [0.

The functioning of the cooler ll, during one phase of its operation, isunder the control of a pair of thermostats 54-55. These thermostats, forthe purpose of convenience, are located in the open portion F of the carbody and are set to close at different temperatures; the thermostat 54being set to close its contacts at 90 F. and the thermostat 55 being setto close at 95 F. The said thermostats 54-55 cooperate with each otherto control the cooling means during different cooling loads. Forexample, the thermostat 54 controls the operation of cooler ll duringnormal cooling loads. When the cooling requirements exceed the normaldemands, the temperature will rise until the thermostat 55 functions at95 F. The functioning of thermostat 55 energizes to move the valve 49 toa position to recirculate through the cooler I l, the previously cooledair vented from the several rooms B, C, D and E.

In addition to the thermostats above referred to, the system includesthree additional thermostats designated 56, 51 and 58. Said thermostat56 is located in the body of the car and is set to function at 100 F.Its contacts are connected in parallel with the contacts of the ductthermostat 53. Consequently, during the cooling cycle when the ducttemperature may be below the functional setting of said duct thermostat53, but the interior temperature of the car is 100, the said thermostat56 will function to deenergize the overhead heater l0 and therebyprevent reheating of the previously cooled air. The thermostat 51 islocated outside the enclosed space H so as to respond to the outsidetemperature. It is set to function at 50 F. and is so connected in thesystem that any time the outside temperature stands below 50 F., thecooling element H is made ineffective, but any time the outsidetemperature stands at or above said 50 F. the

cooling element H is made effective for use in the event that cooling isrequired.

The thermostat 58 is located in the enclosure so as to respond to thetemperature of the enclosure as a whole. It is set tofunction at 60 F.and is so connected in the electrical system that it may be used tocontrol the car when the car is temporarily out of service, for exampleduring lay-over periods at a railway terminal.

Heating phase of system Referring now to the wiring diagram shown inFig. The various control elements are shown deenergized, with theseveral switches M M M M in their open position and the switches M and Mare in their closed positions.

Lay-over heating During a lay-over period of the car, as herein assumed,the switches M and M are closed so as to put the heat supply under thecontrol of thermostat .58. So long as the temperature outside theenclosure Il remains below 50 F. (the functional setting of thermostat51) and the temperature inside the enclosure as a whole remains belowthe functional setting of thermostat 58 (60 F.), the solenoid 59 of amain supply valve 60 (Fig. 1) remains deenergized and the valve is heldopen by a spring 6! to supply heating medium to the floor radiators 23.The heating medium will flow through each of the floor radiators, sincethe admission valves 36 thereof are held open (see Fig. 8) by springpressure when their actuating solenoids 38 are deenergized. As soon asthe temperature of the enclosure I! rises to 60 F., the thermostat 58functions to close an energizing circuit through a solenoid 69 of relayH to energize the heat supply valve solenoid 53 and thereby closes theheat supply valve 60 (Fig. l). The said energizing circuit for relay I-Ileads from positive line 63 through resistor 64, wires 65-456, closedswitch M thermostat-58, wires 61-68, relay coil 69 and wire 10 to thenegative line H. p The circuit closed through said relay H forenergizing the main valve solenoid 53 leads from positive line 63through wires 12-13, closed contact 14 of relay H, wire 75, switch Mvalve solenoid 59 and wires 75- 11 to the negative line I l. The sameresults are obtained by the closing of a circuit through the outsidethermostat 51. Consequently, it will be apparent that whenever theoutside temperature rises to or above 50 F., the relay H is energizedand the supply of heating medium to all floor radiators 23 is shut off.

Normal heating During the normal heating cycle, the switches M M M M andM are closed, but switch M is open. The closing of the switch M directsenergizing current through a motor 18 for operating the blower I6. Thiscircuitleads from positive line 63 through wire [2, switch M wire l9,motor 76, wires and 11 to the negative line I I. This motor circuitremains closed during both the normal heating and cooling cycles of thesystem.

The closing of switch M establishes an electrical circuit to actuaterelay I and thereby close an energizing circuit through solenoid 28 foropening-heat valve 26 to heater l0 (Fig. 6). The circuit for energizingthe relay I leads from positive line 63'through wire 8|, switch M wires82, 82 83, 64, through actuating coil 85 of relay I, wires 66, 81,resistor 88 and wires 89 and 10 to the negative line TI. The energizingcircuit for valve solenoid 28 leads from positive line 63 through wire90, closed contact 91 of relay 1, wire 92, through solenoid 28 andthence through wires 93 and T! to the negative line H. v

The relay I is under the direct control of duct thermostat 53 which islocated in the hot air duct l3 and is setto function at a temperatureacrgcre of =76"l=';' When the temperature atsaid thermostat' 53'rea'ches its functional set-ting, the mercury column of the thermostatcloses a connection between wires 82 and '81 so as to short out therelay coil 85 and thereby deenergize the relay 1. The said thermostat 53is provided with an aimilia'ry heater 94 adapted to receive variabl'eamounts of heat, from time to time, and thereby adjust the thermostat toa lower setting. A fixed amount of heating current /2) is added to theheater 94 for each room thermostat 28 2'6", etc, which becomessatisfied. Inasmuch as the car i! has a total of 26 room thermostats,the thermostat 53 will function at a duct tern-- erature of 63 when allof the room thermostats are satisfied. In this way the thermostat 53 andits relay I are :made available to add heat to the previously "cooledair during the cooling operation of the system "and to vary the amountof heated air delivered during certain phases of theheating cycle. Themeans for directing the variabie amounts of heating current tothermostat 53 will be described in connection with the circuits closedduring the individual control of the "separate rooms.

- Wattage regulator The closing of said switch M in addition to makingthe above circuits available, closes an switch M wires 82, 98, resistore9, wire we,

actuating coil 40! of relay J, wire ill? and resistor H13 to thenegativeline H. The circuit for the auxiliary heater 96 of the wattageregulator thermostat 95 leads from said wire 82 through wires W t-Hi5,resistor 605, wire ml, resistor 98 and wire M9 to said auxiliary heater9G, thence through wires llil, HI closed contact 9? of relay J and wirel 12 to the negative line ll.

Individual room control "The closing of switch alsodirects electricalcurrent through a bus connector- I Hi leading from said wire 82 tosupply electrical current to the solenoids f tilh The .roomthermostatsand their associated relays are connected in circuits leading fromthesaid bus connector H3. In order to minimize the description of the wirediagram, only three of said room thermostats are shown in the diagram,and it will be sufiicient to describe the control circuits for only onesuch thermostat, for example thermostat 2t since the control circuitsforthe other room thermostats E la-Ed and their associated relays Land'M are identical and are connected in parallel with each other.'Consequently, it will be sufficient to desig'nate the correspondingcontrol circuits for the thermostats 24 '24 with like referencecharacters having exponents fc and d, respectively.

The energizing circuit for the auxiliary heater Ei of said thermostat'24 leads from the bus connector! 13, through wire 1 i6, variableresistor 52 movable contact 1-H, wire Ht, through the auxiliary heater51 and th'ence through wires H0, HI, closed contact 91 of relay J andwire ll-2 to negative-line 1-"I. By means of the saiiva-riable resistor52*, as previously described,

the occupant or the room may adjust the runs tion'aiisetting "ofthermostat-24 substantiaiiy 15. That is to say, the adjustment as shownin Figs. 3 and 10 represent a tem erature "setting" of approximately 72F., and it is possible by movement of the contact arm H1 toward the.

can be'ra'isedto function at a room temperature of 8D energizing circuitfor the relay K leads from Wire :1 I 3 through wire i it, resistor H9,and wire tit to the actuating coil ml, and thence through wire iii-'2,resistor 1-23 and wire I24 to the negative line ii. The said energizingcircuit for the relay "is controlled by the thermoe stat 2 t In thisconnection the positive side of the relay coil 12: is connected by wireits to the upper contact-of the thermostat and the nega tive side ofsaid coil is connected through wires I26 and I22 to the lower contact ofsaid thermostat. It will be seen, therefore, that when the mercurycolumn of thermostat 2t stands below its upper contact the relay coil121 is energized to move the relay K into position to close its contacts1 3 and a "and to open its contact 2*. However, when the mercury column"of thermostat 2t rises into engagement with the upper contact of saidthermostat, electric current passes through wires M5 and I26 and throughthe resistor are, wire 224, to the negative line; thereby shorting outthe relay coil iii. Under such condition, the relay is de-energized andassumes the :position shown in Fig. 10 in which the contacts l 3* and iare open and contact 2* is closed. When the relay :K is energized theclosing "of contact i directs additional heating current to theauxiliary heater 5 l The path for this additional current leads fromwire tie, through wire i2], "closed contact l of relay K, wire 1-28,cycle resistor 129 and wires 13c and H8 to the auxiliary heater Bi andthence through wires Hi3, ill, closed contact Q7 of relay J and wire iIE to negative line H. Thecycle resistor 529 has a value of 2"Consequently, the thermostat M will cycle any time the temperature atthe thermostat is within 2 of its functional set-: ting. The said:energization of the relay K opens its contact 2* and, therefore,.deenergizes the solenoid 33 and permits the valve 35 of :the floorradiator to open, said valve being opened by pressure of a spring 3?(log. 8),, and closed by the energization of the said solenoid 38. Thissolenoid, as will be observed by inspection of Fig. 10, is interposed ina branch leading from bus connector H3, through wires lit, 131, closedcontacti of relay K, wire I32, solenoid as and thence through wire lea,resistor lid "and wire H5 to the negative line H. Simultaneously withthe delivery of heating inediuminto the floor heaters, the closing ofcontact 3 of the relayK opens a heating circuit through the coil N5 ofthe heat motor t2 so that the cooling of the motor imparts a slightmovement to the proportioning valve 4! in a direction to supply a largerpro-- portion of hot 'air to the blendedstream of air in branch duct 2:;and to correspondingly reduce the amount of cooler air used in theblended stream.

The said heat motor energizing circuit leads from wire ilZ, through wireuse, closed contact 3 of-reIay K, heat motorbo-il I35, wires 137-438,

.the presence of an abnormal heating load or r 9 'andclosed switch M tothe negative line II. As soon as the relayK is energized to open contact3 the heat motor cools somewhat and thereby moves the proportioningvalve 4| in a direction to reduce the amount of cool air delivered fromair duct section I3 into the branch duct 20.

The closing of relay contact 4 establishes an energizing circuit throughrelay N for closing an energizing circuit through the solenoid 32 ofvalve 30 to supply heating medium to the auxiliary-air heater 22. Thisenergizing'circuit leads from wires 82I36, wire I38, closed contact 4 ofrelay K, wire I39 -I40, resistor I4I, wires, I42 and I43 to actuatingcoil I44 of relay N, thence through wire I45, resistor I46, wire I38,and closed switch M to the negative line II. This circuit closes therelay N and thereby establishes a circuit leading from said wire I39through the upper contact I4? of said relay N through the solenoid 32for controlling said inlet valve 30 (Fig. 7) of the auxiliary air heater22.

The operation of the relay N, as previously indicated, is controlled bythermostat 25, the thermostat being located in the hot duct I3 and-setto function at an air temperature of 76 and is connected through each ofthe floor heat relays 24 etc. Consequently, the relay N will functiononly when the temperture of the air in .the hot duct I3 is below thetemperature of 16 and one of the room thermostats 24', etc., is callingfor heat. Therefore, the relay N and auxiliary air heater 22 will beeffective to add heat to'the air in the return duct I4 only duringduring the cooling cycle of the system.

Weighted average control tact 2 and thereby shutoff the supply of heatto its floor radiator. Simultaneously withthe shutting, off of the floorradiator, a heating circuit is established through the auxiliary heater94 of the thermostat 53 so as to re- -duce the temperature setting ofthis thermo- I52, I53, upper contact I54 of relay J and wire stat. Thisheating circuit leads from wire 82,

through bus connector H3, wires H6, I3l, closed contact 2 of relay K,wire I48, weighted-average resistor I48, Wires I50 and II, through saidauxiliary heater, 94, and thence through wires I55 to the negative lineH. The value of each weighted average resistor I49, I49, etc., is

; one-half degree. Consequently the functioning ofthermostat 24,- etc.,inone enclosed space and the consequent deenergization or its relay K,-L,M,etc., c1oses the energizingcircuitthrough the weighted resistor. I49and thereby directs x sufficient currentto theauxiliary lieaten94' toraise. the temperature of thermostat 153 one-half degree; Ordinarily,there are twenty-six indi- -v id ual enclosures. in a passengercar 'suchas shown in Figs. 1', Z'and 3 of the drawings.

Con-

..sequently, Whenjall of the room'thermostats are satisfied theauxiliary he,ater1,9'4 Qf-Jthermostat 53receives heating currentsufiicient to raise: its temperature 13.- In other words, the thermostat53 is set down from its normal" setting of 7 6 fto.63 F.

-Assum 1ng that the temperaturesiof all enclosed spaces 13, C, D, E,etc., reaches -the; functional gise igg ,o theirj r s e ive hetmo tatsl5,;

10 etc., the inlet valves of the floor radiators -23 and overhead airheaters I0. and 22 are closed jso'af-as to prevent the delivery ofheating medium thereto. If the outside temperature, under the aboveconditions, is below 50, the blower I6,will supply ventilation to thevarious rooms until further heat is required. However, if.thetemperarelay H energizes solenoid 59 to close the irnain valve 60.(Fig. 1) and thereby shuts off the sup,- ply of heating mediumto allfloor radiators '23, It will be observed, however, that a supply;;,ciheating medium is stillavailable for; the, ovenhead air heaters I0. and22 so that theseheaters may function, during the cooling cycle, to; addheat to the previously cooled air, the cheater 412 operating any timethat the duct temperatureis below 76, the functional setting ofthermostat 25, provided that any onev of theindividualspace' thermostats24 9, etc., is also ,calling for ,heat.

The energization of saidrelay H, in addition to interrupting the supplyof heating mediumito all floor radiators, directs, .electric --;currentthrough wire I56, switch M andwire I51 to the upper contact ofthermostat 54 and thereby makes electricity. available for theienergization of cooler relay 0, when thel'temperature,atathermostat 54is suflicient t'oiclose its contacts; This thermostat is positioned inthe body of the .car so as to respond to the temperatureflof.thes'aisleA and the open spaces F-G of the car; .It is set to function at atemperatureof Fgbdtithis functional setting is varied" by electric:current supplied, through the severalweighted average resistorsI49,'I49 I 49d,'etc=;, to electrical'aux'iliary heater I50. The saidauxiliary heater 'l fl0 for the cooling control thermostat 54 isconnected in parallel with the electrical auxiliaryheater 94 of said airheater. control thermostat' .153. Consequently the z-func'tional.settingsfiofi'both thermostats are 'lowe'redf /f forzeach weightedaverage, resistor I I 49, 1439,: 'l 49 x,aetc., whichsis made effective;by the functioning of itsassociated' room: ,thermostat .24 24, 24;wetc:3.:It will be seen, therefore,-that fwhen all iof tithe weighted averageresistors'are effective, :the cooling control thermostat will functionat1=a temperature in space A of 77F. and that the heating controlthermostat 53 will function-ata-duct temperature of 63 F. Consequently,the heating control thermostat 53 will remain closed andthe main heaterI0 will beinoperative 'duringrthe cooling cycle of the control system.However, if the temperature of the cooledzfair in the'duct I3 fallsbelow the temperature setting,of-, thermostat25,-to,-witw76 FL,the-air-rheater .2

made available to add heatrto the cooled air, if and when anyone ofthe-rooms B',iiC;-"D,',etc., fall below the temperature settings'oftheir;;ccntrol thermostats 24 etc; l

The heating current for said heaterilfifl ad 'from a junction I58 inwire I 50, through 'wires I59 to heater I60 and thence, by-wires..lfilizand I53 to closedcontact l54 -of wattage regulator enclosure l1plus the heat added fioy heater Mil sufficient to cause the thermostat5d to function, the relay 0. for cooler H is closed by :an energizingcircuitleading from the lower con- "tact of the thermostat 54 throughwire i162, coil $3 of relay O; and thence .by wires i164 and H tothe'negative line 11. r

- The closing of relay closes a power circuit leading from positive linethrough the various electrically operating mechanisms (not shown)ior'making the cooler 11 effective. This power circuitleadsftrompositive line 63 through wire I65, to closed contact 1% ofrelay 0 and thence by wire IE! to the operating mechanismsassociated-with cooler-l I. Therefore, cooled air will be supplied tothe enclosure as a whole, including each of' -the individual spaces A,B, c, D, etc until the cooling control thermostat t breaks contact, atwhich time the operation of cooler H is discontinuedi However, as hereinbefore indicated, if any one or more of the room thermostatslfl 24, 24etc, should break contact while the temperature in air duct I3 i below7-6 F. the heater 22 will be energized to add .heat

to'the cooled air. It will be also observed, inthis connection, thatwhen arcom "thermostat 2t 24 etc., breaks contact while the temperatureinduct I3 is at'or above 76", for example when such room thermostat hasits higher adjusted setting, such condition will result :merely inremoving a portion of the auxiliary heat from thermostats 53,54,55and56. x

, p v Recirculation. of air' it"the cooling load is such that the coolerl .i,

i operating at full capacity and using only drawn in from outside theenclosure ill, is

unable to maintain the temperature within the 5 rangebetween settings ofthermostats as.

and 55, that is to say, the temperature rises 'sufillliiently to causethe thermostat 55 to func' tion, elements hereinafter described areeneragized- "to change "the. position of air dampers 4'9-+-349"; wherebythe' previously cooled :air is recirculated throughxthe cooler II; Byrecirculattheair through cooler H, the temperature *oIzthe air can belowered .sufiiciently to satisfy temporary abnormal. cooling demandswithout increasingthe size of the :cooling equipment.

'The said dampers 49*49' arenorma'lly in the position indicated in Fig.2, but are shifted to the dotted'line positions by the energization of apair of solenoids I68, I68; These solenoids are .con-

tnected in serieslthrough a movable contact it!) bra relay Pandla'movable; contact I'll of relay H.

The energizing circuit for'the relay P leads from ting ofthermostat d5.At'that time the electric *current is passed 'throughthe contacts ofthermostatss and, therefore, shunts outand deenergizes the relaycoil H5.This condition permits the relay contact 169 to close through the'upper'1 fixed contacts of r elayi' and thereby closes an 1 energizing currentthrough the air damperfactu'a'tin-g coils'168'and I68 soa's to movethese dampers to the dotted' one position shown in 1 Fig; 2andtherebyrecirculata through the cooler H, the previously cooled airyen-ted irom the spaces Whose temperatures are being controlled. Theenergizing circuits through solenoids 168-- its lead from positive line63, wires 12 to contact H?! and the lower fixed contact of relay H(assuming that relay H is energized by the closing of the outsidethermostat 57) and thence through wire H8, closed contact H59 of'relayP, solenoids l-88lii8" and wires H9 and lu to-the negative line H.

The said thermostat 5% for controlling the operation of the air dampersl9l9' set to function at 5 higher than the thermostat 54 for controllingthe cooler ll. In order to maintain this difference for all adjustmentsof the thermostat 54, the thermostat 55 is provided with an auxiliaryelectrical heater l il. It :is connected in parallel with the auxiliaryheaters 94 and 150 and consequently receives the same adjustments fromthe Weighted average resistors I49, its, 149% etc. The energizingcircuit for the auxiliary heater 86 leads from the bus connector I56,auxiliary heater lull, thence through wire lBl, I53 to contact 154 ofthe wattage regulator relay J, and thence through wire 1 55 to thenegative line H. The solenoids loll-46d may also be closed torecirculate the air during the heating cycle of the system when theoutside temperature is below 50? Fahrenheit. In such case the energizingcircuit for said solenoids Hit-468' passes from wire 12 through thenormally closed upper contacts at ill of relay H and thence through WireM3 to the lowerfixed contacts of relay P. During such heating cycle, thethermostat will be normally below .its functional setting and relay Pwill be energized to "The. auxiliary air heater 22, as previously closea circuit through its lower fixed contacts thought-solenoids loll-4B6".

.Rchedtz'ng air during cooling cycle pointed out, willtunction to reheatthe previously cooled air, if the temperature of any one or more of theindividual rooms is below-the functional setting of its thermostat 2 26,24 etc. it

- will be observed, therefore, that the airreheati-ng cooling cycle .ofthe system when th temperature of the individual rooms may b'e above-the I functional "setting. of their thermostats 25 2a,

2M, etc. In this connection the main a'lr'heater N1 .is utilized, underthe control of thermostatil' i. The thermostat 5B :islooated in 'the'body ol the car :so as to respond to the general temperature thereof..It is provided with upper and lower contacts which are connected, bymeans of'wires I82 and [8,3, in parallel 'with the upper and lowercontacts of the thermostat 53, the latter of which is utilized in.controllingthe fair heater I0 during the heating'cycla. The saidthermostat 56, as

. manufactured, :is set toillnctiDn at F'., but

' it :is provided with an electrical auxiliary heater l 84 which isconnected, in parallel with the auxiliaryiheaters of thermostats 53, 54and '55. Conv'sequently, the thermostat 56 is adjusted to lower settingsby the application of heating current through the-several weightedaverage resistors I49, I492 Mil etc., as these various resistors becomeeffective. It will be seen, therefore, that the thermostat 56 may besetdown from 100 F.

to any point above '87 R, depending upon the etc; are satisfied..weightedaverage'resistors I49, I49, I49 etc.,

number of weighted average resistors I49, I49,

I49 etc., which are effective for increasing the volume of heatingcurrent thereto. The electric circuit, through auxiliary heater I84,leads from junction I85 in wire I5I, through wire I86, heating coil I84and wire I81 to its junction I88, with wires I52 and I53, and thencethrough wire I53, closed contact I54, of relay J, and wire I55 to thenegative line II.

In order to further explain the reheating of the previously cooled air,by the main heater I0, during'the cooling cycle of the system, it willbe assumed that all room thermostats 24 24, 24 Under such condition allwill be efiective and thermostats '53, 54, 55 and 55 will each receive13 of auxiliary heat, thereby setting them down 13 from their topsetting.

Under: such conditions the cooperating heating control thermostats 53and 56 will break contact,

at 63 F.,"87 F. respectively and the cooling control thermostats 55 and54 will break contact at 82 F. and 77 F., respectively.

,It is quite plausible and frequently desirable to maintain thetemperature of the cooled air in duct I3 below the functional setting ofthermostat 53, while the temperature within the car remains above thefunctional setting of thermostat 56. Under such condition there would beno reheating of the air, However, when the temperature of the air induct I3 falls below the adjusted functional setting of thermostat 53 andthe temperature of the open section of the enclosure II falls below theadjusted setting of thermostat 56, the main air heater II! is energizedto reheat the air before it is delivered into the enclosure. Suchfunctioning of the main air heater IE! will be stopped when eitherthermostat 53 or 56 makes contact, since the heater control relay I maybe energized by the functioning of either thermostat 53 01256, but it isdeenergized only when contact is broken through both thermostats 53 and56.

Referring now to the modification shown in Figs. 5 and 9: An individualheater designated I89 is arranged in each of the branch ducts 28. Eachheater is supplied with heating medium through pipe I96 and springopened valve I9I. The solenoid for closing the valve I9I is designatedin Figs. 5 and 9 by the reference numeral I35 It is intended that themodification shown in Figs. 5 and 9 shall be controlled by the controlcircuits shown in Fig. 10. In order to accom- .'I3 and I4 at atemperature somewhat less than is required to maintain the desiredtemperature within the several enclosed spaces. The temperature of thisair is boosted by the operation of the individual heaters I89sufiiciently to bring the temperature of the enclosed spaces B, C, D,

, etc., up to the temperature settings of their respective thermostats24., 24, 24, etc.

I In other respects the'heating and cooling system of the modifiedembodiment, including the control circults, for the heating and coolingapparatus may;

be-the same as described in conn'e'ction with Figs. 1 m4, inclusive, andFigs. 6, 7, 8 and 10.

We claim: I 1. In an electrical control system for controllingthetemperature of an enclosure, the combination with apparatus includinga main air duct, means for delivering 'tempered air into said main airduct, branch ducts leading from the main duct for delivering air intodifferent zones of said enclosure, a, heating element for. raising thetemperature 'ofthe tempered air within the main ducts and anelectrically operatedivalve' for controlling the delivery ofheatingmedium to said heater; of means associated with each branch ductfor altering the temperature ofthe airfreceived from the main duct andincluding an electrically energizeddevioe forv varyingthe effectivenessof said temperature altering-means,

' a relay for each electrically energizeddevice, an

energizing circuit therefor, anenergizing circuit for'each electricallyenergized device connected through its associated relay when. the latteris in one position, thermostats located in the several zones of theenclosure and each connected in shunt with the energizing circuit of therelay associated with the zone in which the thermostat islocated,whereby, the effectiveness of thesaid xtemperature alteringdevices are controlled. in relation to the temperatures oftheirassociated zones,a second relay, an energizing circuit for saidelectrically operated valve connected through a closed contact of thesecondirelay and through a closed contact of each zone relay,an'energiz- 'ing circuit for the second relay connected through a closedcontact of each zone relay; connectors defining a shunt circuit aroundthe'second'relay,

anda thermostat located in the'main duct and connected insaid shuntconnections and adapted to break said shunt when the temperature in themain ducts falls below a predetermined value,

whereby the said heating element is made effective only when the ductthermostat together with any one of the zone thermostats are callingforheat. I Y

2. In an electrical'system for controlling the temperature of anenclosure, the combination with a main air-duct forsupplying air for theenclosure, a blower for delivering air into the main duct, meansincluding a main air tempering element for temperingthe air deliveredinto the main duct, and a series of branch ducts for delivering airfrohrr'the main' duct into different zones of the enclosure; of meansassociated with each branch duct for altering the temperature I of theall received from the main duct, separate thermostats located-in eachofthe'zones served by said branch ducts and responsive to the temperatureof their respective zones for controlling the several branch ducttemperature altering means, a duct thermostat responsive to'thetemperature of the tempered air in the main duct for controlling themain air tempering element I and including an electrical heater, andmeans including an element actuated by the functioning of any one of thezone thermostats for closing an energizing circuit through saidelectrical heater, whereby the duct thermostat is adjusted to functionat azlower temperature. '1

3. In an electrical system for controlling the temperature of anenclosure, thefcombination with a, main air duct for supplying airfortheenclosure, a blower for delivering air into the main' duct,- meansincluding a main heating-element and a cooling. element selectivelyoperable .for; tempering the air. delivered intothe main temperaturesettings.

duct, and a series of branch ducts for deliverin air from the main ductinto different zones of the enclosure; of means associated with eachbranch duct for altering the temperature of the received from the mainduct, separate thermostats located in each of the zones served by saidbranch ducts and responsive to the temperatures of their respectivezones for controlling the several branch duct temperature alteringmeans, a duct thermostat responsive to a predetermined temperature ofthe tempered air in the main duct for controlling the main heatingelement and including an electrical heater, a cooling control thermostatset to function at a higher temperature than the said duct thermostatand responsive to the general temperature of the enclosure. forcontrolling said cooling element, an electrical heater for said coolingcontrol ther- 111051721; connectedin parallel with the duct thermostatheater, and means actuated by the functloning of any one of the zonethermostats for closing an energizing circuit of equal heating valuethrough bothsaid electrical heaters, whereby the duct thermostat and thecooling control thermostat are both adjusted to function at lower 4. Inan electrical system for controlling the temperature of an enclosure,the combination with a main air duct for supplying air for theenclosure, a blower for delivering air into the main duct, meansincluding a main heating ele- Ument and a cooling element selectivelyoperable for tempering the air delivered into the main duct, and aseries of branch ducts for delivering air from the main duct intodifferent zones of the enclosure: of means associated with each branchduct for altering the temperature of the air received from the mainduct, separate thermostats located in each of the zones served by saidbranch ducts and responsive to the temperatures of their respectivezones for controlling the several branch duct temperature alteringmeans, a duct thermostat responsive to a predetermined temperature ofthe tempered air in the main duct for controlling the main heatingelement and including an electrical heater, a cooling control thermostatset to function at a higher temperature than the said duct thermostatand responsive to the general temperature of the enclo- .g-izi-ngcircuit of equal heating value through both said electrical heaters,whereby the duct thermostat and the cooling control thermostat are bothadjusted to function at lower temperature settings, a second heatcontrol thermostat responsive to the general temperature of theenclosure for controlling the main heating .element and set to functionat a higher temperature than the said cooling control thermostat andhaving its contacts connected in parallel with the contacts of saidductthermostat, whereby the second heat control thermostat is effective at atemperature above the temperature setting of said cooling controlthermostat, when the duct temperature thermostat is calling for heat, toenergize the main heating element to reheat the tempered air.

5. In an electrical system for controlling the temperature of an.enclosure, the combination with a main air duct for supplying air forthe enclosure, a 1 blower for delivering air into 'the main duct, meansincluding a main heating element and a cooling element for tempering theair delivered into the "main duct, and a series of branch ducts fordelivering air from the main duct into different zones of the enclosure,a vent duct leading from the several zones to the outside atmosphere andcommunicating also with the suction side of the blower, and anelectrically operable damper alternatively positioned to direct thevented air to the outer atmosphere or to direct it to the suction sideof the blower; of means associated with each branch duct for alteringthe temperature of the air received from the main duct, separatethermostats located in each'of the zones served by said branch ductsandresponsive to thetemperatures of their responsive zones for controllingthe several branch duct temperature altering means, a duct thermostatresponsive to a predetermined temperature of, the tempered air in themain duct for controlling the main heating element and including anelectrical heater, a cooling control thermostat 1 with the ductthermostat heater, means actuated by the functioning of any one of thezone thermostats for closing an energizing circuit of equal heatingvalue through both said electrical heaters, whereby the duct thermostatand the cooling control thermostat are both adjusted to function atlower temperature settings, and a damper control thermostat responsiveto the general tempera-. ture of the enclosure for controlling theposition of said damper and set to function at a higher temperature thansaid cooling control thermostat, whereby the position of the vented airdamper is, when the general temperature of the enclosure rises to thefunctional setting of said damper control thermostat, changed to directthe vented air to the suction side of the blower so as to recirculatethe previously cooled air.

6. In an electrical system for controlling the temperature of anenclosure, the combination with a main air duct for supplying air forthe enclosure, a blower for delivering air into the main duct, meansincluding a main heating element and a cooling element for tempering theair delivered into the main duct, and a series of branch ducts fordelivering air from the main duct into difierent'zones of the enclosure,a vent duct leading from the several zones to' the outside atmosphereand communicating also with the suction side of the blower, and anelectrically operable damper alternatively positioned to direct thevented air to the outer atmosphere or to direct it to the suction sideof the blower; of means associated with each branch duct for alteringthe temperature of the air received from the main duct, separatethermostats located in cooling element, an electrical heater for saidcooling'control thermostat connected in parallel 17 I wi h the u tfihormste heate moa s a ua by e fun tion n o a y o pft o' Zohe the m stats forclosing an energizing circuit of equal heating value through bothsaidelectrical heaters, wherebythe duct thermostat and the cooling'com .trolt ermo t a e bo h ad us ed to i ia lower temperature settings, a dampercontrol thermostat responsive to the general temperature of theenclosure (for controlling the position v said am n set to i a tion. t.ah temperature than said cooling control thermof s a w by the pos ion othe r n ed a r d yer. is, w e e n a t mperature 9f tho o osu rises to ef iona set i g o an damper control thermostat, changed to direct the ,vnt dlai o t e su o ide o the low s a duct leading to the room in whichthe thermostat is located, means including a duct thermostat responsiveto the temperature in" the main duct for controlling the main airhea'terfand including an electrical 'heater,jand meansf actuatedby'thefunctioning of the room thermostats for directing heatingcurrentto said electrical heater, whereby the duct thermostat'isadjustedto a'lower temperature setting for each 'i'func ti'oned. roomthermostat.

Inan 'electricalsystem for controlling the te'mperature'of a railway carsubdivided into plurality of rooms, the combination Wl thi a main'airduct extending lengthwise of thecar,

to e mate the pre usly cooled a r a sec nd heat thermostat responsive tothegeneral tema r oi e en os re for cont ing theme-in he ting elemen ans t to uno ion a a i mr erature higher than the said damper controlthermostat and having its contacts connected in parallel with thecontacts of said duct thermostat, whereby thesecond heat controlthermostat is effective at high space temperature, when theductytemperature thermostat is calling for heat, toenergize the mainheating element toreheat the tempered air, and anelectrical heater forthe second heat control thermostat connected inparallel with the heaterof the saidduct thermostat,

cooling control thermostat, and dampercontrcl thermostat, whereby allthermostats just mentioned are set down corresponding amounts upon thefunctioningofany one of the zone thermostats.--

'7. In .an electrical system .for controllingthe temperature of arailway car subdivided into-a plurality of rooms, the combinationwith amain air duct extending lengthwise of the can a blower and mainairheater for delivering tempered air into the :main duct, a seriesofbranch ducts leading from the mainductinto the several rooms of thecar; of,an auxiliary air'heater for adding heat tothe tempered airwithin the :mainduct, means associated with each branch duct. foraltering the temperature o f the-:air received from the main duct,separate 5 therrno stats located in the rooms responsive to thetemperature thereof to ,control the temperature altering means of the;branch duct serving the room in which the, thermostat isl cated, aductthermostat responsive to the temperature of: the

,main duct for controlling the. main air tempering means, a second meansincluding, asecond duct thermostat for controlling, the- .1,. auxiliaryair heater, andmeans including a ,relay actuated by the functioning vofany one of the room thermostats to make the auxiliary vair heatereffective only when the secondjduct thermostat and any one ofthe roomtherrnostats are calling for heat. o V

I 8. Inan electrical systemfor controlling the temperature of a railwaycarj subdivided into" a plurality of rooins, the combination ith, a mainair duct extending lengthwise'lof heflcar', fa

pe red air into the r'nai-n' duct; a series of branch ducts leading fromthe 'mai'ngiduct 'intol', the several rooms ofthe.can.;oiflihdividualair heaters "interposed in the. several branchducts for. addirigfhttt tdthaiir ic i'vegr from the main ,1 duct,thermostats ,lo ated infthe several rooms of the car'andfrspon'sivei tothe Itemperatures therein, each thermostat j controlling the individualheateriassociated the branch blower, and main airneaterforne1 'e'ring'ten'ia blowerCanli main air theater forj'delivering tempered air intothe main duct, a j seriesfof vbranchfducts leading from'the main ,ductinto thefs'everal rooms or the car; of individual "air heatersinterposed in the several branch ducts 'for adding heat to the" airreceived IIQmdihfi main duct, thermostats located in the several roomsof the car and responsive to the temperatures therein,eachthermost'at'controlling the individual heater associated with thebranch duct'le'ading" to theroom'in which the thermostat is located,means including a duct thermostat responsive to the temperature'inthemain duct for controlling the main air heater and including anelectrical heater, an auxiliary heater for each room thermostat,a"""v'ariable resistor interposed in an energizing circuit for saidauxiliaryheater' for adjustably varying the ,functional'setting of theroom thermostat, and

means actuated by the functioning of ther'oom thermostats for directingheatingcurrentftofsaid electrical heater, whereby the duct thermostat isadjusted to a lower'temperature settingjfor eachfuncti'oned' roomthermostat.

1 0. In 'a'n'e'lectrical system for controlling the temperature of arailway car subdivided into a plurality of rooms', th'e'combin'ation'witha f'mairi air duct extendinglengthwise of tl 'ie car,a blower and main air'heaterffgn delivering tempered: air into the] mainduct, a j series ofibranch ducts'leading from the main duct intotheseveral' rooms of the'car; or" individual air heaters interposedinthe several'hranch ducts (for adding heat" to the air receivedi f maintduct, thermostats located in the-several -ri "the rooms of the car andv responsivefto fthe tem peratures therein, each thermostat controllingthe individual "heater associated with" :-the 'branch' duct leading to,the'room inwhich the thermostat is located, meansincludingductthermostat responsive .to the temperature in'th'e main duct forcontrolling the main air'h'eate'r and including an electrical heater,"an' auxiliary heater for each room thermostat, a variableresistorinterpos'ed in an energizing; circuit for said auxiliary heaterfor adjustably varying 'the functional setting of the'room*'thermostat',-a relay actuated by the functioning of the roomthermostats for directing heating current to said electrical heater,whereby the duct' thermo'stat i'sjadjusted to a lowertemperature'settingfor each functioned room thermostat, and means connected throughsaid relay for adding' ad-, ditional amounts of heating current'to theauxlatter is below its control point.

11. In an electrical system, for controllingthe temperature of a'railway'carsubdivided- -into a plurality of rooms and open sections, thecombination of a main air duct extendingleng thili'ary heater of theroom thermostat when the "wise of the car and provided with" branchducts leading into the several rooms, means for delivering air into themain duct,. and means comprising a main air heater and a coolingelements'ele'ctively operable for tempering the air', 'aduct'thermostatresponsive to the temperature in the'main duct for controlling themainheater, a cooling control thermostat responsive to the generaltemperature of said open sections for controlling the cooling elementand set to function at a higher temperature than said duct thermostat,separate air heaters for adding heat to the air received in the severalbranch ducts, individual room thermostats responsive to the temperaturetherein for con trolling the individual air heater for the branch ductserving the room inwhioh the thermostat is located, auxiliary electricalheaters for-adding heat to each of the thermostats specified, variableresistors for adjustablyvarying the heating current supplied to" theauxiliary heaters of the'room thermostats, and means comprising arelayassociated with "each room thermostat for directing equal amounts ofheating current to. the auxiliary heaters of the saidduct thermostatand, to the cooling control thermostat, wherebyrboth of the lastmentioned thermostats are adjusted, in equal amounts to lowertemper-ature settings by the functioning of each room thermostat.

, l2.'In an'electrical system for controlling the ample tion at a highertemperature than said duct thermostat, separate'air heaters for addingheat to the air received in the several branch ducts, individual roomthermostats responsive to the temperature therein for controlling theindi-v vidual air heaterfor the branch ductserving' the room inwhichthethermostat is located, auxiliary electrical heatersforadding heat toeach of the thermostats specified, variablev resistors {for adjustablyvarying the heating-current supplied to the auxiliary heaters of theroom ,thermostats, means comprising a relay associated witheach roomthermostat for directing equal amounts of heating currentto theauxiliary heat- 'ers ofthe said duct thermostat, and to-the coolingcontrol thermostaawhereby bothof the last mentioned thermostats areadjusted, in equal amounts to lower temperaturesettings by thefunctioning'of :each room thermostat, means for recirculating thepreviously cooled air through the cooling element, arecirculating'coritrolthermostat s etto function at a higher temperaturethan the cooling control thermostat and responsive -to the temperatureof said open sections for controlling said air recirculating means, andan auxiliary heater for the last mentioned thermostat connected inparallel with theauxiliary heater of said duct thermostat,

whereby the functional setting of the recirculating control thermostatis set down equal amounts by the functioning of each room thermostat.

13. In an electrical system for controlling the temperature of a railwaycar subdivided into a plurality of rooms andopen sections, thecombinationof a main air ductextending'lengthwise of the carandprovidedwithbranchducts leading into the several rooms,gnieans fordelivering air into the main duct; and means comprising a main airheater and a cooling element selectively operable for tempering the'air,a duct thermostat responsive to thetemperature in the main duct'forcontrolling the main heater, a cooling control thermostat-responsive tothe general temperature -ofsaid' open sectionsfor controlling thecooling'element and set to function'at a higher temperature thansaidd'uct thermostat; separate air heaters' for adding heat to the airreceived inthe" 'severalbranch ducts, individualroomthermostatsresponsive to the temperature therein forc6ritrol1in'gthe' individualair heater for'the branch duct serving theroom in which the thermostat i's located,- auxiliary electrical heatersfor adding-heat to each of the thermostats specified; variable resistorsfor adjustably varying:the heating'current supplied tothe'auxiliary"heaters-of the room thermostats, "means comprising-a'relay associated With'each room thermostat' for directing equal amountsof heating current to" the auxiliary heaters of the said duct thermostatand to the cooling control thermostat, whereby both of the lastmentionedthermostats areadjusted, in equal amounts to lowertemperature-settings by the functioning of each room thermostat, meansfor recirculating the previously cooled air through the cooling element,a, recirculating control thermostat setto function' at a highertemperature than the. cooling control. thermostat and responsive to thetemperature of said open sections;- for controlling said air'recirculating' means,-a reheat control thermostat set to function at ahigher -temper'ature than said recirculating control-thermostatandresponsive to the'temperatureof said opensections of the car 'forcontrolling the main heater, the contacts of the reheat controlthermostat being connectedin parallel with the contacts-of said ductthermostat, wherebythe' 'reheatcontrol thermostat is effective by theopeningof its contacts athigh car temperatures, when the duct thermostatis calling-for heat, to energize the mainheating element and -reheat-therecirculated air, and auxiliary heaters for? the recirculating controlthermostat and'the' reheat control thermostat connected in parallelWith'the auxiliary heater of the duct thermostat 14. In an eIectri'oaLstern forcontrolling the temperature" of a railway car-"subdivided intoa pluralityofrooms, a combination with a main air duct includingupperandlower duct sections extending magma/seer the carfor "containingpre-tempered air of diiferent temperatures, a series ofbranch ductsleading from the main duct into the several rooms and'communicatin'g attheir inlet ends with adjacent ports formed in both upper andlower-sectionsof the main air duct, whereby streams of air from bothfsections of the main duct'a're blended insaid branch ducts and deliveredinto saidrooms; and a proportioning valve in each branch duct forvarying the amount of different tempera'tured ail-"delivered intothe'branch ducts; of means for controlling the temperature of the'airthemain duct comprisin'ga' main air heater and a thermostat responsive.tothe temperatur'e in the main duct for controlling the efiectivenessofthemain 21 heater, separate room thermostats located in each of theseveral rooms and responsive to the temperature therein for varying theposition of the proportioning valve in the branch duct serving the roomin which such room thermostat is located, whereby the temperature of theblended air discharged from the branch ducts is controlled in relationto the temperature of the room served by such branch duct, an auxiliaryair heater for adding heat to the air in the lower section of the mainduct, a thermostat in the main duct responsive, below a predeterminedtemperature therein, for making the auxiliary air heater effective, andmeans including an auxiliary heater for the first mentioned ductthermostat and means actuated by the functioning of any one of the roomthermostats for adjusting said first mentioned duct thermostat to alower temperature setting, whereby the adjustment of the first mentionedduct thermostat represents the accumulative affect of all functionedroom thermostats.

15. In an electrical system for controlling the temperature of a railwaycar subdivided into a plurality of rooms, a combination with a main airduct including upper and lower duct sections extending lengthwise of thecar for containing pretempered air of different temperatures, a seriesof branch ducts leading from the main duct into the several rooms andcommunicating at their inlet ends with adjacent ports formed in bothupper and lower sections of the main air duct, whereby streams of airfrom both sections of the main duct are blended in said brach ducts anddelivered into said rooms, and a proportioning valve in each branch ductfor varying the amount of different temperatured air delivered into thebranch ducts; of means for controlling the temperature of the air in themain duct comprising a main air heater and a thermostat responsive tothe temperature in the main duct for controlling the effectiveness ofthe main heater, separate room thermostats located in each of theseveral rooms and responsive to the temperature therein for varying theposition of the proportioning valve in the branch duct serving the roomin which such room thermostat is located, whereby the temperature of theblended air discharged from the branch ducts is controlled in relationto the temperature of the room served by such branch duct, an auxiliaryair heater for adding heat to the air in the lower section of the mainduct, a thermostat in the main duct responsive, below a predeterminedtemperature therein, for making the auxiliary air heater effective, andmeans including an auxiliary heater for the first mentioned ductthermostat and means actuated by the functioning of any one of the roomthermostats for adjusting said first mentioned duct thermostat to alower temperature setting, whereby the adjustment of the first mentionedduct thermostat represents the accumulative affect of all functionedroom thermostats, means for recirculating the air through the airtempering means, and means including a thermostat having a highertemperature setting than the first mentioned duct thermostat andresponsive to the general temperature of the car for controlling thesaid air recirculating means,

EDWARD A. RUSSELL. TIMOTHY J. LEHANE. ROBERT E. PIDGEON.

- REFERENCE S CITED The following references are of record in the fileof this patent:

UNITED STATES PATENTS Number Name Date 2,182,449 Parks et a1 Dec. 5,1939 2,188,775 Locke Jan. 30, 1940 2,218,468 Haines Oct. 15, 19402,323,236 Parks et al June 29, 1943 2,372,839 McGrath 'Apr. 3, 1945

